Balancing two-crank engines.



F. B. K. SGHUBERT.

BALANCING TWO CRANK ENGINES.

. APPLICATION FILED AUG. 5, 1911. 1,027,775.

Patented May 28, 1912.

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F. B. K. SCHUBERT.

BALANCING TWO CRANK ENGINES.

APPLICATION FILED AUG. 5, 1911.

1,027,775, Patented ma 28, 1912.

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, I UNITEDSTATESPATENT oFFIoEf \FFANZ BIQERNHAF'D KARL.sCHUFER'l-, OF HAMBURG, GERMANY, ASSIGl VOR TO GOM I ram: or nnsnmss & JACOBI acrmnensnnnscnarr, or HAMBURG; GERMANY.

'- BALANCING- rwo-cmx ENGINES.

. Specificationofletterslatenfl Patented May28,1912. Application filed August 5, 1911. Serial No. 642,577. 1

i To all whom it may concern the present invention to drive the piston of o Beit. known that I, FRANZ BERNHARD a singlemylinder engine; Fig. 2 representsa P KARL "ScHUBEnT, a subject of the German vertical sectional diagrammatic view of a Emperor residing at 63 Hammerlands'trasse, balanced explosion motor; Fig. 3 is a dia- 5 Hamburg, in the German Empire, have ingrammatic view representing 111 end eleva 60 vented certain new and useful Improvements 't-ion a balanced engine of'the kind iniquesin Balancing Two-Crank Engines, of which -ti0n; Fig. 4 is a plan of Fig. 3; and FigsQ-S the following is a specification. and 6 are'similar views as Fig. 4 showing An' endeavor has hitherto been made in modified arrangements of the counter- 10 connection with single cylinder engines to weights; I 65', balance the forces of inertia by causing the Similar letters of reference refer to like piston to act by means of a cross head or the parts throughout the figures. like on two connecting rodsmounted on two Tlleinvention can best be explained with coaxial oppositely running crank shafts reference to the diagrammatic views Fig. 3

which are provided with rotating countem and 4 of Whlch Fig.3 represents in end (ale-70 weights. If the counter-weights are suitably vation an engine of the kind in question that selected this arrangement permits of bal-. it is desired to balance with itscranks hori ancing both of the moments of the rotating zontal and Fig. 4 shows the two crank shaftsmasses and tliemoments of the reciprocating of this engine in plan. In these illustra 2 masses, as these counterweights furnish or tlonsm indicates the piston of the single 76 en 'ender forces which completely counter-- cylinder'engme which is connected by a ba ance those due to the inertia of the rotat--' cross-head g and the two connecting rods 1) ing masses of the cranks and of the lower and 71 to the cranks 7c and k of the two connecting rod ends,' and which by them recoaxial oppositely running shafts w and w.

2 sultant in the direction of the axis of the The dotted line Z) (Fig. 3) or the point I) I piston correspond to the reciprocating (F 1g. 4) represents the axis of the piston.

' masses, while theresultant of the said en- In order to balance the moments of the rogendered forces'perpendicularly to the axis tating masses a counterweight g" or g corof the piston. are always equal and opposite. responding to the moment of the rotating This known method of balancing as applied masses is arranged as nearly as possible in to single cylinder engines does not, however,. the plane a or a of the cranks or connecttake into accountthe moment which is proing rods opposite each of the cranks 7: and duced by the fact that'- the lanes of the k For balancing the reciprocatingmasses cranks or connecting rods an" consequently there are also arranged opposite the cranks v those of the counterweights are located at but in the central lane a passing through an interval ordistance apart one from the the axis b of the piston- (Fig. 4) additional other. These moments, the lever-arm or .counterweights c and c by means of two I magnitude of which is determined by the disks a: and 3 running one within the other; distance of the counterweights, are however these counterweights present equal moments 40 unbalanced in this known arrangement and corresponding to half the reciprocating act as rolling moments in a plane passing masses. It will readily be understood that through theaxis of the crank shaft perpenthe centrifugal forces of these two counterdicularly to the axis of the piston as they weights invariably engender a resultant in tend to rock the crank to and fro in this 'the direction of theaxis of the piston which 'planethat is to say, to rotate them on the is equalvand opposite to the inertia of the 9 axis of the piston. Although these rolling piston and so forth while the'res'ultants of moments have not hitherto been neutralized both centrifugal forces in the plane perpen this is effected according to the present indicular to the axis of the piston-mutually vention with the result that a complete or neutralize each other in each crank position approximately complete balancing of the so that an oscillation or rocking of the crank entire machine is effected in the manner shafts around the axis b of the piston in the hereinafter described with reference to the direction of the arrows indicated in Fig. 4' accompanying sheets of drawings in which-- is prevented. From the arrangement of Figure 1 is a perspect-iveview of an elecbalancing rotating masses on each crank tric motor constructed in accordance with in their plane independently and of neuright and tralizing reciprocating masses by rotating counterweights arranged opposite the cranks in the central plane of the engine as a whole, therefore results a mathematically complete balancing effect if each connecting rod be considered as consisting of two ends with a connecting rod the mass of which may be neglected; this assumption which departs but little from the actual facts greatly simplifies the matter. 1

In practice it is frequently impossible to arrange the counterweights o and 0 in one and the same plane, that is to say the central plane of the engine. In this case, either the one or the other of these counterweights may bedivided into two weights 0 c (Fig. 5) and arranged in planes located to the left of the central plane in such a manner that the ideal sum of these two smaller counterweights rotates or acts in the central plane of the engine.

The four counter-weights (Fig. 4;) or the five counterweights (Fig. 5) can also be combined to form two counterweights, that is to say the two counterweights belonging to each crank shaft can be combined to form asingle counterweight as the weights g and g (Figs. 4 and 5) serving for balancing the rotating masses and the weights 0 and c, or c and a 0 respectively, necessary for balancing the reciprocating masses are located opposite the corresponding cranks at an angle of 180 in the same radial plane 0" (Fig. 3). This combination of the weights g and c and g and c (Fig. 4) or g and c c (Fig. 5) furnishes two counterweights cl" and d (Fig. 6) each of which is equal to the sum of the weights g and 0 and g and c or g and c 0 respectively. These weights d and (Z are not located either in the planes of the cranks or in the central plane of the engine but in intermediate planes 0 and c (Fig. 6) the distance between which and the central plane is determined in such a manner that the moment of the combined weight (Z or d is equal to the sum of the moments of the weights 9 c or g 0 or g c c to be replaced. Owing to the fact that the balancing weight-s d d are located laterally of the central plane of the engine they leave room for a central bearing in which the two crank shafts w and w can be supported.

A practical embodiment of the invention is illustrated in Fig. 1 as applied to a vertical engine of the kind referred to. This arrangement shows in perspective an elec tric motor driving the piston 72?. of a singlecylinder engine through two cranks k and if, two connecting rods 1)" and p and a cross head Q. The armature shaft w of the armature j which rotates-in a counterarmature clockwise direction carries one crank in while the magnet ring it rotating in a clockwise direction forms one piece with the other shaft in and crank For the sake of clearness in Fig. 1 the upper part of the rotating magnet ring is omitted and the shown in dotted lines. The counter-weights g and 9 arranged opposite the cranks are the balancing weights for the rotating masses. The masses moving upward and downward including the rolling or rocking moments in a plane perpendicularly to the piston-axis are balanced by a counterweight 0 arranged opposite the crank k in the armature and by two counterweights 0 0 arranged opposite the crank 0 on the magnet ring in accordance with the diagrammatic View Fig. 5.

Fig. 2 represents a balanced explosion 'motor in which also two co-axially arranged crank shafts rotate in opposite directions and are moved upward and downward by means of connecting rods actuated by a common piston m. The counterweights d and d which are two in number as shown dia-.

grammatically in Fig. 6, are here attached to two flywheels s and .9 arranged in proximity to the central plane of the engine. As already stated in explaining Fig. 6 these counterweights are equal to the sum of the rotating and reciprocating masses to be balanced and are located at such distance from the central plane vof the engine as corresponds to the proportion of the two masses which is ascertalnable from a comparison of their moments.

In the two engines illustrated in Figs. 1

and 2 a complete balancing effect for practical purposes is obtained.

I claim: p I

In an engine, in combination with a single cylinder, of two pitmen and two cranks on two concentric independently and oppositely rotatable shafts adapted to be engaged by said pitman rods, a balance Weight for each crank adaptedtobalance the rotating and reciprocatin parts and arranged between the longitudinal axis of the cylinder and the central plane of rotation of that crank which said combined balance weights being so weightedand at such a distance from the longitudinal axis of the cylinder that the rolling moments produced by the said balance weights are equal to the rolling moments produced by the rotating parts.

In testimony whereof I aflix my signature in presence of two witnesses.

FRANZ BERNHARD KARL SCHUBERT. I Witnesses:

MAX A. G. LEMOKE, ERNEST H. L. MUMMENHQFF.

it is to balance, 

